At present, a set of biopsy needles is generally used to collect tissue in the affected part in a human body.
The set of biopsy needles comprises double needles composed of an outer needle in the form of a hollow tube and an inner needle to be inserted into the outer needle. It is punctured into an predetermined part in a human body and thereafter the outer needle is pushed forward to protrude from the tip of the inner needle whereby the tip of the outer needle can cut tissue in the affected part and the tissue can be collected inside the tip of the outer needle. Thereafter, the double needles is pulled back from the human body so that the tissue in the predetermined part can be collected.
In the conventional set of biopsy needles, however, the double needles can not surely cut off and collect the tissue in the affected part because the outer needle can cut off the tissue in the affected part by being protruded straightly, that is, only by being pushed and cutting after the double needles is punctured into the predetermined part in the human body.